The present invention relates to a disk-typed chipper.
A drum-typed chipper for producing chips from logs having a relatively large diameter is well knwon, for example, by Japanese Patent Publication No. 7081/1974. In such type of chipper, the drum is adapted to receive the cut chips at the inner peripheral surface thereof so that they tend to lie flat on the inner surface of the drum due to centrifugal force at a raised rotating speed. In this case, it is difficult to remove the cut chips from the interior of the drum. For such reason, the rotating speed of the drum chipper is normally limited to 25-120 rpm. Consequently, the drum chipper has a low productivity and high price while it is large in structure. The drum chipper also has a disadvantage in that it requires logs to be cut which have been pre-cut to a predetermined length. Moreover, the drum chipper has a further disadvantage in that logs are fed to the cutter thereof through a converged hopper. This causes the logs to be cut under compression so that the logs will be damaged. Furthermore, it is difficult to obtain chips having the desired thickness as they expand after cutting. Finally, the logs are cut by the drum chipper along the arcuately curved periphery thereof so that the chips will be curled. This will reduce the compaction rate of chips that can be charged in the cooking digester.
As is apparent from the foregoing, the drum-typed chipper cannot produce chips of uniform size and damage the wood fibers.